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dc1948af

DEMO MANUAL DC1948A

Quick start proceDure

Demonstration circuit 1948A is easy to set up to evalu-

ate the performance of the LT3090. Refer to Figure 1 for

proper measurement equipment setup and follow the

procedure below:

NOTE. When measuring the input or output voltage

ripple, care must be taken to avoid a long ground lead

on the oscilloscope probe. Measure the input or output

voltage ripple by touching the probe tip directly across

the terminals of the input or output capacitors. See

Figure 2 for proper scope probe technique.

1. Use JP2 to set the desired output voltage.

2. Put JP4 on ON position.

3. With power off, connect the input power supply to VIN

and GND.

4. Turn on the power at the VIN.

NOTE. Make sure that the VIN voltage does not exceed

–36V.

5. Check for the proper output voltages:

NOTE. If there is no output, temporarily disconnect the

load to make sure that the load is not set too high or

is shorted.

6. Once the proper output voltages are established, adjust

the loads within the operating range and observe the

output voltage regulation, efficiency and other param-

eters.

NOTE. Make sure that the power dissipation is limited

below the thermal limit.

Figure 2. Measuring Input or Output Ripple

Figure 1. DC1948A Proper Equipment Setup